Brake locking mechanisms to deter or impede theft of vehicles such as automobiles, trucks, trailers and the like are well known. However, such mechanisms heretofor known have had one or more disadvantages. For example, in U.S. Pat. Nos. 3,482,666; 3,874,747; 4,007,815; and Re. 29,913; a brake locking mechanism is installed at each brake to prevent movement of an otherwise hydraulically or pneumatically operated brake rod mechanism. This involves installation of a brake locking device at each brake, generally modifying each existing brake to accommodate the locking mechanism, and installing an auxiliary control system to operate the brake locking mechanism.
Another type of brake locking mechanism involves positioning a valve in the brake power fluid line between the master cylinder and the brakes as seen in U.S. Pat. Nos. 4,040,675; 3,973,803; 3,653,730; 3,625,573; 3,617,100; and 3,515,442. With this mechanism, the brakes are locked in the applied position by pressurizing the brake fluid and then closing the valve in the brake fluid line to prevent release of the pressure. However, this type of mechanism has the disadvantage that installation in an existing brake system is complicated by the necessity of breaking the hydraulic fluid line. Further, it is generally a possibility in such systems that the valve in the brake line could close during operation of the vehicle, and thereby render the brakes inoperable while the vehicle is in motion.
My earlier U.S. Pat. No. 4,873,824, discloses a brake locking mechanism for use with an automobile vehicular brake system having one or more fluid operated brakes, a master cylinder and an actuator for reciprocating a piston in the cylinder to apply and release the brakes. The locking mechanism has a housing adapted to fit between the master cylinder and the actuator having means for reciprocating the piston responsively to the actuator including a ratcheted rod within the housing and a means for locking the reciprocating means with the piston in the brake applying position including a pawl operatively associated with the ratcheted rod. The locking means is remotely controlled from a control mechanism in the driving compartment which may be mechanical or electrical.